would be interesting not only to show if it is up which could be probably done by a weakaura which just check for a blockchance which is greater than (blockchance from gear + 40%) probably. More interessting would be a timer which shows how long the restduration of the higher blockchance would be.

You could set up a WeakAura to watch for when you cast Word of Glory (Trigger -> Event -> Combat Log -> Cast Success -> Word of Glory), add a custom timer of 15 seconds (though it would always assume that you cast it with 3HP) and then take it from there.

Do you use TipTac? this would also allow you to check for sure what the SpellID of the buff is, I don't have the t15 2p so I wouldn't be able to tell you for sure whether it would work or not.

Dael, tanking since the warriors couldn't be bothered to do it in Hyjal.